A183870 n+floor(sqrt(5n-5)); complement of A183871.

1, 4, 6, 7, 9, 11, 12, 13, 15, 16, 18, 19, 20, 22, 23, 24, 25, 27, 28, 29, 31, 32, 33, 34, 35, 37, 38, 39, 40, 42, 43, 44, 45, 46, 48, 49, 50, 51, 52, 53, 55, 56, 57, 58, 59, 61, 62, 63, 64, 65, 66, 67, 69, 70, 71, 72, 73, 74, 76, 77, 78, 79, 80, 81, 82, 84, 85, 86, 87, 88, 89, 90, 91, 93, 94, 95, 96, 97, 98, 99, 101, 102, 103, 104, 105, 106, 107, 108, 109, 111, 112, 113, 114, 115, 116, 117, 118, 120, 121, 122

Offset

1,2

Links

Table of n, a(n) for n=1..100.

Formula

a(n)=n+floor(sqrt(5n-5)).

Mathematica

a=5; b=-5;
Table[n+Floor[(a*n+b)^(1/2)], {n, 100}]
Table[n-1+Ceiling[(n*n-b)/a], {n, 80}]

Crossrefs

Cf. A183871.

Sequence in context: A370267 A002481 A370268 * A186497 A193627 A256792

Adjacent sequences: A183867 A183868 A183869 * A183871 A183872 A183873

Keyword

nonn,easy

Author

Clark Kimberling, Jan 07 2011

Status

approved